Clamping fixture



April 10, 1962 G. SVOBODA CLAMPING FIXTURE 3 Sheets-Sheet 1 Filed June 8, 1960 wvavroe G. SVOB 0A 1962 G. SVOBODA CLAMPING FIXTURE April 10,

' 3 Sheets-Sheet 2 Filed June 8, 1960 //WE/\/ r02 7 6. SVOBOA ATZ'OEN Y 3,029,072 CLAMPING FIXTURE George Svoboda, Albuquerque, N. Mex., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed June 8, 1960, Ser. No. 34,749 Claims. (Cl. 269-44) This invention relates to clamping fixtures, and more particularly to a fixture for clamping a piece part securely in position while a work operation is performed thereon.

It is standard practice to form certain surfaces of a piece part by a milling operation while the part is held in position in a suitable clamping fixture, and at the present time such a procedure is followed in the manufacture of armature pawls to be used in step-by-step telephone switching systems. Since the milled surfaces of the pawl must be formed to a very close tolerance and be located precisely with respect to other elements of the pawl, it is essential that the pawl be positioned in the clamping fixture properly with respect to the milling cutters and then be securely held in this position while the milling operation is taking place. Further, the construction of the clamping fixture should be such that the pawl may be clamped readily in the fixture in preparation for the milling operation and may be removed readily from the fixture when the milling operation is completed.

An object of this invention is to provide a new and improved clamping fixture for clamping a piece part in a fixed position during a work operation on the piece part.

A further object of this invention is to provide a new and improved clamping fixture wherein the piece part first is positioned properly in the fixture and subsequently is clamped in position so that a work operation may be performed on the piece part.

Another object of this invention is to provide a new and improved clamping fixture wherein a piece part readily may be positioned and clamped in the fixture in preparation for a work operation, and subsequently readily may be removed from the fixture after the work operation is completed.

With these and other objects in view, the present invention contemplates a clamping fixture which is mounted on a slide table and includes a base having a nest formed therein for receiving a step-by-step armature pawl. A separate loading fixture is provided in which the pawl is positioned for loading it into the nest. is loaded into the nest it engages and moves a springbiased ejector mechanism which normally extends into the nest, and the ejector mechanism closes a control circuit to operate an actuator secured to a movable cam carrying bar mounted in the base. Movement of the cam carrying bar in one direction by the actuator causes cams mounted thereon to move a plurality of positioning and clamping members into engagement with opposite sides and the top of the pawl to secure it in the nest. The slide table, clamping fixture and pawl are then moved to a pair of conventional milling cutters for the milling operation. As the clamping fixture is moved back to its initial position after the milling operation is completed, a cam opens the control circuit and the actuator moves the cam carrying bar in a reverse direction, allowing suitable springs to move the various clamping members to their initial positions and release the pawl, whereupon the spring-biased ejector mechanism ejects the pawl from the nest.

Stats Patent As the pawl operation, and in actual use receiving a pivot pin whereby wardly at an angle as at 12a.

of the outwardly extending part of the connecting portion.

Other objects, advantages and novel features of. the

invention will become apparent upon consideration of the following detailed description in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view of a clamping fixture constructed according to the present invention and mounted on the bed of a conventional milling machine;

FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1, certain parts having been omitted for purposes of clarity;

FIG. 3 is a cross-sectional enlarged View taken along the line 3-3 of FIG. 1;

FIG. 4 is a partial cross-sectional view taken in the same plane as FIG. 3 and showing an armature pawl as it appears when clamped in the clamping fixture during a milling operation;

FIG. 5 is a cross-sectional enlarged view taken along the line 5-5 of FIG. 2;

FIG. 6 is a cross-sectional view taken along the line 66 of FIG. 5;

PEG. 7 is a plan view of a cam for operating certain of the clamping members;

FIG. 8 is a perspective view of a step-by-step armature pawl; and

FIG. 9 is a partial elevational view of the step-by-step armature pawl shown in FIG. 8 as it appears in operating position.

Referring to FIGS. 1 and 2, a clamping fixture 20 constructed according to the present invention, and including a mounting plate 21, is clamped to a slide table 22 of a conventional milling machine by bolts 23, the heads of the bolts being positioned in a slot 24 formed in the slide table to permit adjustment of the fixture in a conventional manner. A conventional type air valve 26 (FIG. 1) is similarly mounted on the slide table 22 by bolts 27, and controls a conventional air ram 28 at the rear of the clamping fixture 20 for operating the various clamping members subsequently to be described. Adjacent the front end of the clamping fixture 20, a piece part loading fixture (described in more detail hereinb'elow) is secured to the bed 29 of the milling machine (FIG. 2) by suitable screws for loading an armature pawl it) (FIG. 8) into the clamping fixture.

As shown in FIG. 8, the armature pawl 10 is of a substantially channel shape and includes a pair of upstanding parallel legs 11 and a connecting portion 12. The connecting portion 12 has an outwardly projecting arm 13 thereon, which is utilized to properly position the pawl relative to a step-by-step switch rod 19 (FIG. 9) with which it cooperates. Each of the legs 11 has an aperture 14 formed therein, the apertures 14 receiving positioning pins in the clamping fixture 20 during a milling the finished pawl may be mounted on a pivoted carrying arm (not shown) in the telephone switching system. The connecting portion 12 of the pawl 10 extends outwardly to the right, as viewed in FIG. 8, and then is bent up- One of the opposite sides 12 merges with the arm 13, and the other side merges with one of the legs 11, by means of smooth curved surfaces 15, and the connecting portion 12 ultimately terminates as its outer end in a fiat milled surface 16, an arcuate milled blunt edge 17, and a curved milled surface 18, all formed precisely relative to the angle of bend of the outer end of the connecting portion and located precisely relative to the apertures 14. As shown in FIG. 9,

in operation the fiat surface 16 acts as a lifting surface for operating the cylindrical step-by-step switch rod 19 in a vertical direction, with the arcuate blunt edge 17 successively engaging in annular notches formed in the rod and the curved surface 18 providing clearance so as to permit such engagement. Since the pawl and the manner of operation of the pawl form no part of the present invention, further discussion thereof is not considered necessary. It will be apparent, however, from the above description that the milled surfaces 16 and 18 must be oriented and located with reasonable accuracy with respect to the apertures '14 and the legs 11.

The slide table 22 is mounted on the bed 29 of the milling machine in a conventional manner (not shown), whereby the slide table, the clamping fixture 20 and a pawl 1E clamped in the fixture at the front end thereof, may be moved to the right as viewed in FIG. 1, either manually or by any suitable automatic means. The pawl may thereby be moved into juxtaposition with a pair of conventional type milling cutters 31, 32 carried on a support 33 which is slidably mounted on the bed 29 of the milling machine for vertical movement in a conventional manner. When the support 33 is in its normal upper position, the milling cutter 31 is so positioned vertically and horizontally with respect to the pawl 10 in the clamping fixture 20 that as the pawl is moved past the cutter it will perform a preliminary milling operation on the outer end of the connecting portion 12 of the pawl (FIG. 4). When the pawl has been positioned beneath the milling cutter 32, however, the milling cutter 32 must be moved downward by downward movement of the support 33 to engage the pawl 10 to finish machining the desired surfaces and edges of the pawl.

As shown best in FIG. 3, the clamping fixture 20 includes a box-like base or support including a base plate 36, a recessed main body 38 and a front cover plate 39, all secured together by screws as shown. This base is, in turn, mounted on the clamping fixture mounting plate 21 by suitable bolts as shown in FIGS. 1 and 2.

Referring to FIGS. 1 and 3, the upper portion of the main body 33 has a pair of longitudinally extending and axially aligned rectangular slots 42 and 43 formed therein, the rearwardmost slot 42 being considerably wider than the forwardmost slot 43. The bottom and side surfaces which form the upper front end of the slot 43 provide a portion of a nest 44 for receiving the armature pawl 10. Secured in the slots 42 and 43 by suitable screws is an elongated member 46, which is formed at its upper front end, as shown in FIGS. 3, 4 and 5, so as to provide surfaces complementary to surfaces on the legs 11 and connecting portion 12 of the pawl 10, thus completing the nest 44.

The front end of the main body 38 is straddled by an inverted substantially U-shaped clamping member 43 (see FIGS. 1, 2 and which includes spaced vertical legs 49 and an upper portion 51 interconnecting the legs and extending transversely across the top of the main body. The vertical legs 49 of the clamping member 48 are disposed in vertical slots (FIGS. 1 and 2) formed by shoulders 53 on the main body 38 and laterally spaced surface portions 54 of the front cover plate 39, whereby the clamping member is vertically movable on the main body. The clamping member 48 is biased upwardly by springs 55 disposed in recesses formed in the lower ends of the clamping member legs 49 and bearing against the base plate 36, as shown in FIGS. 2, 3 and 5. The springs 55 have vertically disposed pins 57 positioned therein which extend downwardly into recesses in the base plate 36 to provide lateral support for the springs when the clamping member 43 is in its uppermost position.

The upper portion 51 of the clamping member 48 is disposed across the top of the main body 38 above the nest 44 and projects downwardly along its front end at 51a (FIGS. 3 and 4), whereby when the clamping mem- 4 ber 48 is moved downward, a carbide insert 59 in the upper portion 51 will engage the top surface of the outwardly extending part of the connecting portion of the armature pawl 10 to clamp the pawl in the nest. The clamping member upper portion 51 includes a slot 51b which extends rearwardly and then upwardly (FIG. 3) so as to provide a passage for the pawl arm 11 when the pawl 10 is moved into position in the nest 44, with the upwardly extending portion of the slot 51b receiving the arm 11 when the clamping member 43 is in a clamping position as shown in FIG. 4.

As shown in FIGS. 3 and 5, the lower ends of the clamping member legs 49 have a bolt 61 secured therebetween and disposed in vertical slot 62 formed in the lower portion of the main body 38, so as to extend across the recessed portion of the main body. Snugly mounted on the bolt 61 are a pair of cam-engaged rollers 63 which are spaced apart by a sleeve 64. The rollers 63 are engaged by a pair of laterally spaced earns 66 secured to opposite sides of a longitudinally slidable and substantially rectangular actuating bar 67 disposed through suitable apertures in the main body 38 and the cover plate 39, respectively. When the actuating bar 67 is moved to the right as viewed in FIG. 3, the cams 66 will move the bolt 61 and the clamping member 48 downwardly against the action of the springs 55 to the clamping position shown in FIG. 4. The action of the cams 66 on the rollers 63 tends to cause rotation of the rollers on the bolt 61, whereby the rollers immediately begin to wear grooves in the bolt and thus be precluded from outward transverse movement with respect to the earns 66.

Referring to FIG. 5 and the upper portion of the main body 38 on each side of the nest 44, a pair of pin carrying members 71 are slidably disposed in transversely aligned apertures 72 and are confined in the apertures at the outer ends thereof by the clamping member legs 49. The inner ends of the slidable members 71 adjacent the nest 44 carry armature pawl clamping and positioning pins 73 which are resiliently biased toward the nest by means of springs 74 bearing against plugs 76 threaded into the outer ends of the slidable members. The ends of the pins 73 adjacent the nest 44 include projections 77 which are designed to extend into the nest when the slidable members 71 are moved toward each other, whereby the projections 77 engage in the pivot pin apertures 14in the armature pawl 10 (FIG. 8), and in an aperture 46a in the elongated member 46, when the pawl is positioned in the nest.

As shown in FIGS. 5 and 6, the apertures 72 housing the slidable members 71 open downwardly into the recessed portion of the main body 33, whereby rocker arms 79, pivoted to the main body 38 by suitable screws, may extend upwardly into engagement with the slidable members 71 for moving the slidable members toward and away from each other. The upper end of each of the rocker arms 79 has a gear segment 79a which is formed thereon and engages a toothed rack portion 71a on a respective one of the slidable pin carrying members 71. The upper ends of the rocker arms 79 are biased away from each other by a compression spring 81 disposed through a portion of the main body 38, whereby the slidable pin carrying members 71 are also biased away from each other and away from a position in which the projections 77 on the pins 73 extend into the nest 44. Movement of the slidable members 71 toward each other is provided by the lower ends of the rocker arms 79 ex tending downwardly into engagement with an operating cam 83 (FIGS. 3, 5 and 7) secured to the top of the slidable substantially rectangular actuating bar 67 by suitable screws. The configuration of the cam 83 (FIG. 7) and its location on the bar 67 is such that the positioning pins 73 will have come into full engagement with the legs 11 of the armature pawl 10 before the vertically movable clamping member 48 engages the armature pawl to secure it in position.

The cam carrying actuating bar 67 is actuated by the air cylinder 28, Which includes a spring biased piston (not shown) and a piston rod secured to the rear extremity of the bar 67 by a pin or other suitable means as shown in FIG. 3. The air cylinder 28 is secured to the clamping fixture support plate 21 by means of a bracket 88 and suitable screws, as shown in FIG. 2. Air is supplied to and exhausted from the air cylinder 28 by theair valve 26 through air lines 92 in a manner now to be described.

Referring to FIG. 1, mounted on the right hand side of the main body 38 by suitable screws is a control switch 93 for controlling the air valve 26 and which includes an electrical circuit-closing button 94 and a circuit-opening and switch-reset button 96.

As shown in FIGS. 1 and 3, the top central portion of the main body 38 has an upwardly opening and transversely extending slot 98 formed therethrough perpendicular to and separating the longitudinally extending slots 42 and 43. The transverse slot 98 houses a spring-biased pivoted lever 99, which forms a part of a combination air valve actuating and piece part ejector mechanism, and which extends through the transverse slot 98 under the nest forming member 46, as shown. The spring-biased lever 99 is pivoted at its left hand end, as viewed in FIG. 1, on a bracket 101 secured to the main body 38 by suitable screws, and at its right hand end is designed to move rearwardly to engage and depress the circuitclosing button 94 of the control switch 93. The pivoted lever 99 is normally biased away from the switch-button 94 by a compression spring 102 engageable therewith at its midpoint and disposed in a groove 103 formed in the main body 38 at the bottom of the rearwardmost longitudinal slot 42. Pivoted on the lever 99 at its midpoint is the rear extremity of a piece part ejector pin 104, the ejector pin 104 being slidably disposed in a groove 106 formed in the main body 38 at the bottom of the upper longitudinal slot 43, with its front extremity having an upwardly projecting portion 104a extending upwardly into the nest 44. Thus, as an armature pawl is moved into the nest, it will engage the ejector pin portion 104a and move the ejector pin 104 and pivoted lever 99 rearwardly (FIG. 4) to depress the circuit-closing switch button 94.

Depressing of the switch button 94 closes an electrical circuit to energize a solenoid in the air valve 26 and open the air valve to admit air to the air cylinder 28. The air cylinder 28 then moves the cam carrying bar 67 to move the slides 71 and pins 73, and the clamping member 48 into clamping position. This latter movement causes a stop member 108 (FIGS. 1 and 2) welded on the upper rear extremity of one leg 49 of the clamping member 48 to engage the right hand end of the pivoted lever 99 to retain the lever in its button depressing position.

As the clamping fixture 20 is moved to the right in FIG. 1 toward the milling cutters 31, 32, as previously indicated, either manually or by any suitable automatic means, the switch-reset button 96 engages a spring-biased cam 109 which is mounted for one-way pivotal movement on an upstanding bracket 111 secured to the bed 29 of the milling machine, but the button is not depressed at this time since the cam is free to pivot out of the path thereof as shown in FIG. 1. However, when the work operation is completed and the clamping fixture 20 is moved back to the left as viewed in FIG. 1, pivotal movement of the cam 109 is prevented by a pin 112, and the switch button 96 will ride over a beveled edge of the cam and be depressed to reset the control switch 93. Thus, the electrical circuit is opened to deenergize the solenoid in the air valve 26, whereby the air valve allows air to be exhausted from the air cylinder 28. The air cylinder 28 then moves the cam carrying bar 67 back to its original position (FIG. 3) and the clamping members 43, 73 are biased from clamping engagement with the pawl 11) by the springs 55, 81 back to the positions shown in FIGS. 3 and 5, allowing the spring-biased ejector mechanism 99, 102, 104 to eject the milled pawl at a point between the milling cutters 31 and 32 into a suitable receptacle (not shown).

The loading fixture (FIGS. 1, 2 and 3) for loading the armature pawl into the nest 44 includes a mounting bracket 121 secured to the bed 29 of the milling machine by suitable screws, as previously indicated, and having an upper portion disposed in a plane substantially parallel to the bottom'surface of the upper longitudinal slot 43 in the main body 38. A plate 122 is welded to the upper portion of the bracket 121 and has a longitudinally extending slot 123 formed therein for receiving a slidebiasing spring 124. As shown best in FIG. 1, a pair of spaced apart plates 126 and 127 are secured to the top of the plate 122 by suitable screws to form a slide groove 129 and are undercut as at 126a and 127a along their length so that a longitudinally movable slide 131 in the groove 12 9 is confined therein against vertical movement. The slide 131 has a first pin 132 suitably secured thereto and extending downwardly into the slot 123 in the plate 122 between the spring 124 and the upper end of the slot, and has a second pin 133 suitably secured thereto and projecting upwardly into an elongated slot 134 (FIG. 1) formed in one end of a slide actuating lever 136 pivoted to the member 126 by a screw 137. The groove forming members 126 and 127 further include oppositely facing surfaces 12Gb and 1271) (FIG. 1) at the ends thereof adjacent the nest 44, which are each contiguous to a respective surface 15 (FIG. 8) on the armature pawl 10, whereby the pawl may be firmly seated in the loading fixture for loading into the nest 44.

Operation In operation, the operator positions the slide table 22 as shown in FIG. 1, as by moving the table against a suitable stop (not shown), to align the nest 44 in the main body 38 with the groove 129 in the loading fixture 120. The slide-actuating lever 136 is then pivoted manually or by any suitable automatic means in a clockwise direction (FIG. 1) so an armature pawl 10 seated in the --enters the nest 44 in the main body 38 it engages the upwardly projecting portion 104a of the ejector pin 104 and moves the ejector pin to the rear in the groove 106. This movement of the ejector pin 104 also moves the pivoted lever 99 to the rear to depress the circuit-closing button 94, whereby the air cylinder 28 is actuated by the opening of the air valve 26 to move the bar 67 and cams 66, 83 forwardly. As the cam 83 is moved, it pivots the lower ends of the rocker arms 79 away from each other and the gear segments 79a on the rocker arms cooperate with the slidable member toothed rack portions 71a (FIG. 5) to move the slidable members 71 toward each other, so that the pins 73 come into engagement with the sides of the armature pawl 10 and the projections 77 on the pins enter first the pivot pin apertures '14 in the pawl 10 and then the aperture 46a in the member 46. At the same time the earns 66 cam the bolt 61 and the clamping mem ber 48 downwardly to engage firmly and clamp the pawl 10 securely in position, as shown in FIG. 4.

The operator now moves the slide table 22 to the right as shown in FIG. 1 and as the armature pawl 10 passes the milling cutter 31 the milling cutter will perform a preliminary cut in both a vertical and a horizontal plane on the outwardly extending end of the connecting portion 12 (see FIG. 4). As the slide table is moved further to the right it comes into abutment with a stop member (not shown), so located that the armature pawl 10 will be positioned-vertically under the milling cutter 32. The milling cutter support'33 is then moved downwardly by the operator so that the milling cutter 32 engages the pawl and may perform a final cut on the fiat surface 16 (FIGS. 8 and 9), if so desired, and cut the arcuate edge 17 and the curved surface 18, after which the support 33 is raised to its original position.

The operator next moves the slide table 22 back to its original position as shown in FIG. 1, during which movement the switch-reset button 96 on the switch 93 engages and is depressed by the cam 109 whereby the air valve 26 is closed, the air is exhausted from the air cylinder 28, and the actuating bar 67 and the cams 66, 83 are returned to their original positions. As the bar 67 and the earns 66, 83 move to their original positions, the springs 55, S1 bias the clamping member 48 and the positioning pins 73 back to the positions shown in FIG. 5, whereby they release the ratchet pawl 10 and allow the spring 192 to move the ejector pin 104 so that the projecting portion 104a of the ejector pin engages and ejects the ratchet pawl 10 from the nest 44.

While a fixture according to the present invention has been shown in connection with the holding of a step-bystep armature pawl during a milling operation, it is contemplated that the fixture could be used for the holding of other types of piece parts in other types of work operations.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of this invention. Numerous other arrangements may be readily devisedby those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. Apparatus for positioning a piece part in a clamping fixture and subsequently ejecting the piece part from the clamping fixture which comprises, a base including a nest for receiving the piece part, a loading fixture including a piece part receiving groove designed to be aligned with said nest, a slide in said groove movable toward said nest to position the piece part in said nest, a spring-biased lever pivoted on said base, a slidably mounted ejector in said base, said ejector being pivotally connected adjacent one end to said lever at a point spaced from the point of pivot of said lever on said base, the other end of said ejector extending into said nest, clamping means mounted on said base, means for actuating said clamping means, said actuating means being movable between a first position wherein said clamping means are disengaged from the piece part and a second position wherein said clamping means are in clamping engagement with the piece part, means for controlling the movement of said actuating means, a switch on said base engagcable by said pivoted lever when a piece part is moved into said nest by said slide whereby said switch is operated to actuate said control means and move said actuating means to said second position, means for operating said switch to deactuate said control means whereby said actuating means returns to said first position, and means for moving said clamping means away from clamping engagement with the piece part to release the part, whereupon said spring-biased lever moves said ejector to eject the part from said nest.

2. Apparatus for clamping a channel-shaped piece part during a work operation thereon, wherein the piece part has a pair of spaced legs having pivot pin apertures formed therein, and has a connecting portion which extends longitudinally outward beyond the legs and requires a machined surface accurately located thereon with respect to the apertures, which comprises, a base including a nest for receiving the piece part, slide means for moving the piece part into said nest, opposed pin carrying members in said base on opposite sides of said nest and slid- .able transversely with respect to said nest, pins resiliently mounted in said members and designed to engage in the pivot pin apertures when said members are moved toward .each other, pivoted rocker arms each having means at 8 one end thereof interengaged with means on a respective one of said movable members, resilient means biasing said ends of said rocker arms away from each other, a clamping member including a pair of spaced substantially parallel legs and a portion interconnecting said legs, said clamping member being mounted in spaced slots in said base for vertical movement with respect to said nest, a connecting member secured between said legs and disposed in elongated vertical slots formed in said base, a resiiient means biasing said clamping member away from a clamping position, a movable member extending through said base, cam means on said movable member engageable with said pivoted rocker arms and with said connecting member whereby upon movement of said movable member in one direction said clamping pins and said portion of said clamping member interconnecting said legs are moved into clamping engagement with the piece part, actuating means secured to one end of the movable member for moving the member, means for controlling said actuating means, a spring-biased lever pivoted on said base, a slidable ejector pivoted at one end to said lever at a point spaced from the point of pivot of said lever on said base, the other end of said ejector extending into said nest, a switch mounted on said base and engageable by said lever when a piece part is positioned in said nest to operation and subsequently ejecting the piece part when the work operation is completed, which comprises a base including a nest for receiving a piece part, substantially opposed operating members adjacent opposite sides of said nest and movable toward and away from one another and said nest, pins carried by said operating members and designed to engage in apertures in the piece part when said operating members are moved toward each other, thereby to position and to hold the piece part in said nest, pivoted rocker arms each having means at one end thereof interengaged with means on a respective one of said operating members, a clamping member including a pair of spaced substantially parallel legs and a portion connecting said legs, said clamping member being mounted for movement in a direction substantially perpendicular to the direction of movement of said operating members,

so that said portion connecting said legs engages and clamps the piece part against said base when said clamping member is in clamping position, a connecting member sceured between said legs, movable cam means engageable with said pivoted rocker arms and with said connecting member for sequentially moving said pins and said clamping member into engagement with the piece part to secure it in position in said nest, drive means for moving said cam means, a spring biased movable ejector mechanism extending into said nest whereby when a piece part is moved into said nest it engages and moves said ejector mechanism, a switch engageable by said movable ejector mechanism for actuating said drive means, and means for moving said pins and said clamping member away from engagement with the piece part to release the piece part, whereupon said spring biased ejector mechanism ejects the part from said nest.

4. Apparatus for clamping a piece part during a work operation and subsequently ejecting the piece part when the work operation is completed, as recited in claim 3, in which said ejector mechanism includes a spring biased pivoted lever engageable with said switch for actuating said drive means, and a slidably mounted ejector drivingly connected adjacent one end to said lever at a point spaced from the point of pivot of said lever, the other and a slide in said groove movable toward said nest to end of said ejector extending into said nest whereby when position the piece part in said nest. a piece part is moved into said nest it engages said ejector to move Said lever. References Cited in the file of this patent 5. Apparatus for clamping a piece part during a work 5 UNITED STATES PATENTS operation and subsequently ejecting the piece part when Y 1 the work operation is completed, as recited in claim 3, 2:23: which further comprises a loading fixture including a piece 2302878 Mum u N 4 1942 part receiving groove designed to be aligned with said nest, 

